Hydrothermal Preparation of a Series of Luminescent Cadmium(II) and Zinc(II) Coordination Complexes and Enhanced Real‐time Photo‐luminescent Sensing for Benzaldehyde

Two cadmium(II) and two zinc(II) coordination complexes with diverse structural motifs, [Cd₂(HL)I₃H₂O] · H₂O ( 1 ), [Cd₂(H₂L)₂(H₂O)₄] · 2SO₄ · 14H₂O ( 2 ), [Zn₃(L′)₂(H₂O)₆] · 4H₂O · 2(NO₃) ( 3 ), and [Zn₃L'₂(H₂O)₂Cl₂] · H₂O ( 4 ) [H₂L = 1,1‐bis(5‐(pyrid‐2‐yl)‐1,2,4‐triazol‐3‐yl)methane; H₂L′ = 1,1‐bis(5‐(pyrid‐2‐yl)‐1,2,4‐triazol‐3‐yl)methanone] were synthesized through a hydrothermal method. These coordination complexes were characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction (PXRD), FT‐IR spectroscopy, and photo‐luminescent experiments. Single crystal structural analysis revealed that 1 – 4 belong to polynuclear coordination compounds. PXRD analysis of 1 – 4 unambiguously confirmed the purity of the as‐synthesized coordination compounds. It is the first time to synthesize coordination compounds based on H₂L′, which reacted from the original material H₂L through in‐situ hydrothermal conditions. In addition, photo‐luminescent experiments revealed that 1 – 4 have real‐time sensing effects for benzaldehyde through fluorescence quenching. For 1 – 4 , the photo‐luminescent quenching effect for benzaldehyde was also compared and the coordination complexes 3 and 4 based on H₂L′ have higher photo‐luminescent quenching effect than compounds 1 and 2 .